Study On Fault Diagnosis Simulation For Screw Compressor Based On Vibration Signal

As the screw compressor is used increasingly as the core equipment in the petrochemical industry, the reliability and security of its operation is receiving more and more attention. So the screw compressor fault diagnosis research is very necessary. In order to reduce the failure rate of the product, correctly carry out predictive maintenance and reduce the loss of service, the screw compressor fault diagnosis system development is urgent. Thus in this paper, the rotor dynamic model for screw compressor is established by finite element method, then the vibration characteristics of the main fault simulation and experimental validation are studied, and then obtain the fault characteristics based on vibration signal which required for its fault diagnosis. In this paper, according to the working principle and characteristics of the screw compressor, based on ANSYS software with finite element method rotor dynamics model is established, the model for transient response and steady state response are analysis respectively. In the analysis focus on the free modal and support modal analysis, and with the transient dynamics method, the time-varying failure excitation loaded, by simple harmonic excitation under the rotor meshing frequency simulating mesh bad fault, rectangle excitation under meshing frequency simulating rotor and the casing scratches, and simple harmonic excitation under rotating frequency simulating unbalance fault, Successful obtained the velocity, displacement, acceleration and reaction time domain response of the reaction, moreover through discrete Fourier method to obtain the frequency domain response spectrum; Through the system simulation under the different frequency excitation of the obtained response relationship of frequency variation of each fault. Through simulation of the equilibrium level, frequency, unbalance to obtain the unbalanced fault response and its relations.Firstly by the hammer modal method, the freedom rotor modal is verified(first-order natural frequency verified); Secondly the screw compressor vibration signal collection and analysis system based on Lab VIEW is compiled. Based on the system, the meshing bad fault, rotor and the casing scratches fault and imbalance fault are test verification respectively. The highly contact ratio of test results and simulation results, prove the validity of the system modeling and simulation.